Inter Turku came into this match on a 10-match unbeaten run in the league and 17 without defeat in all competitions, but with seven of their last 11 ending in draws, they were perhaps more fragile than their record showed.
Gnistan proved that to be the case with two strikes in the first half - Joakim Latonen sent Adeleke Akinyemi racing through to score midway through the half, then on the stroke of half-time, Ilmari Kangasniemi was sent off for bringing down Latonen inside the box, and the fouled man sent the goalkeeper the wrong way from the penalty spot.
Handball inside the area from Pakwo Gnanou early in the second half allowed Alie Conteh to halve the deficit with a spot-kick of FC Inter's own, but that would not be enough, as the home side failed to respond to KuPS going five points ahead. Gnistan move up to fourth with their third win in a row.
A second win in a row has taken HJK to within three points of Inter Turku, and they picked up three points against TPS thanks to Santeri Haarala, who was alert to a rebound following a blocked shot, taking it down and guiding it into the bottom corner. TPS remain in eighth, five points off the top half having lost three of their last four.
Ilves have joined both TPS and today's opponents Lahti on 22 points after their second victory in a row. The only goal is one Lahti goalkeeper Osku Maukonen won't forget in a hurry, as his attempted clearance was charged down by Jardell Kanga, ricocheting the ball into the net. Lahti stay above both TPS and Ilves on goal difference, but their three-game winning run is over.
